chantbell



(No Model.)

J. GHANTRELL.

BIT STOCK.

No.284,2'75. I Pat-entedSept.4.1883.

UNITED STATES Joruv CHANTRELL, OF BRIDGEPORT,

CONNECTICUT, ASSIGNOR TO HAZEL- TINE 8t CHANTRELL, OF SAME PLACE.

BIT-STOCK.

sPEcir'rcATIoN forming part of Letters Patent No. 284,275, dated September 4, 1883.

Application filed May 16, 1883. (No model.)

To aZZ whom it may concern.-

Be it known that I, J OHN OHANTRELL, of

7 Bridgeport, in the county of Fairfield and State lower ends and hold it solidly in position.

of Connecticut, have invented certain new and useful Improvements in Bit-Stocks; and I do hereby declare the following to be a full, clear,

. holding-pressure on the bit is released; and

with these ends in view my invention consists in the parts and combinations of parts, as'will be more fully described, and pointed out in the claims. a

In the accompanying drawings, Figure 1 is a view in perspective of my improved stock, Fig. 2 'is a longitudinal sectional view of the same. Fig.3 shows the parts detached, and Fig. 4 is a View showing a modified form of the follower and holding-jaws.

A represents a bit-stock of ordinary shape, the outer or free end of which is enlarged and provided with a socket for the reception of the holding-j aws and follower. This hollow end or head is open on opposite sides nearlythrou'ghout its entire length, and isprovided about midway with the shoulders a, which limit the upward movement of the sleeve 13, and with the screw-threaded portionb, with which the said sleeve engages. This head is provided internally, near its -outer end, with the outwardly-converging inclined bearing-surfaces 0, against whichthe outer ends of theholdingjaws C bear, while thelower or inner ends of the said jaws are supported on. the inwardlyconverging inclinedsufrfaces (Z of thefollower D. The holding-jaws C, areeach provided,

near their outer ends, with the beveled or inclined bearing-faces e, which latterrest and V bearagainst the inclined bearing-surfaces c of the head. The inner fades of both holding-j aws are recessed for the reception and retention of the bit. The inner ends of the holding-jaws are provided with the inclined bearing-faces e, which latter rest and moveon the inwardly-converging inclined surfaces d of the'follower D. Each jaw is provided at its inner end with a downward extension or continuation, f, which latter rest in the open slot 9 of the follower D and hold the jaws in position against displacement. The inner or adjacent edges of the jaws C are made parallel with each other throughout that portion of their length that is employed in grasping the shank of the bit, while their lower portions diverge, and

hence there is insured a rocking movement of the jaws on one another. The followerD rests and is adapted to be moved in the slotted head and force the holding-jaws toward the outer open end thereof. The inclined inner or lower facesof the holdingjaws, being supported on the inclined faces of the follower, will allow the jaws to descend by their gravity, and by reason of the diverging faces of thelower ends of the jaws their upper ends will be separated for the insertion ofthe shank of the bit. When wardly between the jaws, the lower ends thereof are forced apart, and hence are moved outwardly on the inclined faces of the follower. This movement serves to force the outer ends of the jaws together, and hence the simple act of inserting the shank causes the jaws to grip it evenly throughout its length. By lowering the sleeve B the follower is then forced outwardly, which has the effect of forcing both ends of the jaws together, and thus tightly clamping the entire length of the bit-shank. As soon as the bit is released, the jaws are also released and settle down on the follower, the lower inclined ends thereof seeking the lowest possible position. This forces together the lower ends of the jaws and 'opens the upper ends thereof, and leaves the bit free to be withj drawn. The j aws are also retained against accidental displacement by the pin 9 which latter is rigidly secured to one jaw near its lower end, and passes through a corresponding opening in the other jaw. i

The follower D rests on and is supported by the collar F, which latter encircles the screw-threaded portion 6 of the head of the stock, and is free to move longitudinally thereon. This collar is provided on its outer edge, on diametrically-opposite sides, with the bit-shank is inserted and forced downthe open slots or recesses h, in which the inner ends of the follower rest. As the follower is only free to move longitudinally, it follows that the collar F is only free to move in the.

same direction. The collar F rests 011 the annular shoulder z of the sleeve G, and its movement, and consequently the movement of the follower and holding-j aws, is dependent on the movement of the sleeve. The lower half of the sleeve B, or the portion thereof below the shoulder i, is internally screw-threaded for engagement with the screw-threaded portion 1) of the head of the stock, while that portion thereof above the shoulder 13 is adapted to overlap the smooth portion of the head' outside or beyond the shoulder a. The outer surface of the sleeve is roughened to enable it to be grasped without slipping. When'the sleeve B is turned in the proper direction, the collar is forced outwardly, and in turn moves the follower and the holding-j aws. When the motion of the sleeve is reversed, the sleeve moves inwardly on the screw-threaded portion of the head of the stock and leaves the jaws, follower, and collar free to follow by gravity. By means of the pin 9, the jaws are caused to move simultaneously, which not only prevents one jaw from falling lower than the other, but also automatically centers the bit and obviates trouble and inconvenience, which would necessarily result if the jaws were not held in the same plane.

Instead of slotting the follower and passing the jaw extensions f through the said slots, the follower can be cut away on opposite sides, and the extensions f, instead of branching from the center of the inner ends of the jaws, can connect therewith, respectively, on opposite sides, so as to straddle the follower instead of passing through the same. This construction is shown in Fig. 4. of the drawings.

The device is exceedingly simple in construction, is durable and effective in use, and can be manufactured at a small initial cost.

I am aware that bit-stocks have been constructedwith jaws that are forced together by means of inclined faces' on the jaws and the socket in which the jaws are located, and that claim to such construction and combination of parts.

It is evident that slight changes in the construction and relative arrangement of the several parts might be resorted to without departingfrom the spirit of my improvement, and hence I would have it understood that I do not confine myself to the exact construction shown and described, but consider myself at 6 bearings on the head and the follower, said Q jaws being constructed with their adjacent sides outwardlydiverging at their lower ends, substantially asset forth.

2. In a bit-stock, the combination, with a stationary socketed head, an adjustable screwthreaded sleeve engaging therewith, and a ring supported on a shoulder formed on said sleeve, said ring provided with slots, of a follower adapted to engage in the slots in said ring, said follower constructed with converging inclined bearings, and holding-j aws having inclined bearings that engage with inclined bearings on the head and the follower,-substantially as set forth.

3. In a bit-stock, the combination, with a stationary socket-head having inclined bearings c c, the adjustingsleeve B, ring F, and follower D, having inclined bearings d d, of the jaws 0, having inclined bearings 0 ee 6, extensions f, and pin 9, substantially as set forth.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

J OHN CHANTRELL.

Witnesses:

F. B. KEPPY, H. E. BOWSER. 

